Avalanche Forecast for Sunday, March 15, 2020

This information was published 03/15/2020 at 6:45 AM.

NOT THE CURRENT FORECAST

This is an archived avalanche forecast.


The Bottom Line

Generally safe avalanche conditions exist in the Presidential Range. The greater mountain hazard today is the potential for a long sliding fall. If venturing into steep terrain today, match your climbing equipment to your comfort level. For some, this is crampons and an ice axe, while for others, this may include harnesses, a rope, and protection to mitigate the fall hazard. Match your objective to your skill and comfort level on icy terrain today. Avalanche danger is LOW; avalanches are unlikely.

2020-03-15 Printable


Mountain Weather

Yesterday, light snow showers on the summit all morning produced 0.7” of snow. This arrived while wind was blowing from the west between 80-100mph.

Today, as high pressure moves into the region, skies will clear, temperatures will decrease, and wind will slow down. Current wind is from the NW around 40mph and should linger there for the day.

Tomorrow should be clear with temperatures slightly warmer than today. Wind from the NW will shift to the SW, starting the day 15-20mph and increasing late in the day toward 50mph. The next forecast precipitation is 2” of snow on Tuesday.

Primary Avalanche Problem – Wind Slab

Wind Slab

Aspect/Elevation

Likelihood

Size

You may find wind slabs that are shallow and isolated to terrain features that can collect drifting snow. Extreme wind speeds Friday and Saturday scoured many slopes to the melt/freeze crust, eliminating the avalanche problem in many areas. If you can find wind slab, it’s likely wind hammered and quite firm.

  Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Forecast Discussion

Snow quality on Mount Washington right now is less than optimal for skiing thanks to the mid-week warm-up leaving a widespread melt/freeze crust that in some places resembles concrete and in others, a nasty breakable crust. For those who are more excited about the climb up than the ride down, the climbing conditions are quite nice. Ice got a refresh and snow slopes offer fast cramponing. With great climbing and poor skiing comes the long, sliding fall talk. Take time to read this observation submitted last night about how difficult it is to arrest a fall in these kinds of conditions. The big takeaway for me from this story is the recognition of the hazard and the chosen line of descent based on the fall hazard. Glad to hear it all turned out and thanks for sharing the lesson.

Additional Information

The Sherburne and Gulf of Slides ski trails are snow covered to Pinkham Notch.

Details on daily snowfall totals, precipitation type, total depth of snow and other information can be found on our page devoted to snow study plot data. Click here to check it out.

Recent snowpack and avalanche observations can be found here and on Instagram. Your observations help improve our forecast product. Please take a moment and submit a photo or two and a brief description of snow and avalanche information that you gather in the field.

Please Remember:

Safe travel in avalanche terrain requires training and experience. This forecast is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.

Avalanche danger may change when actual weather differs from the higher summits forecast.

For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.

Posted 03/15/2020 at 6:45 AM.

Helon Hoffer
USDA Forest Service
White Mountain National Forest